Enhance eBPF C code generation by incorporating context-specific includes for kprobe programs while maintaining vmlinux.h usage. Update TC-specific includes to define action constants inline, avoiding header conflicts.

Author: congwang-mk

src/context/tc_codegen.ml

@@ -68,12 +68,19 @@ let tc_field_mappings = [
 
 (** Generate TC-specific includes *)
 let generate_tc_includes () = [
-  "#include <linux/bpf.h>";
-  "#include <bpf/bpf_helpers.h>";
-  "#include <linux/if_ether.h>";
-  "#include <linux/ip.h>";
-  "#include <linux/in.h>";
-  "#include <linux/pkt_cls.h>";
+  "/* TC action constants - defined inline to avoid header conflicts with vmlinux.h */";
+  "#ifndef TC_ACT_UNSPEC";
+  "#define TC_ACT_UNSPEC        (-1)";
+  "#define TC_ACT_OK            0";
+  "#define TC_ACT_RECLASSIFY    1";
+  "#define TC_ACT_SHOT          2";
+  "#define TC_ACT_PIPE          3";
+  "#define TC_ACT_STOLEN        4";
+  "#define TC_ACT_QUEUED        5";
+  "#define TC_ACT_REPEAT        6";
+  "#define TC_ACT_REDIRECT      7";
+  "#define TC_ACT_TRAP          8";
+  "#endif";
 ]
 
 (** Generate field access for TC context *)

src/ebpf_c_codegen.ml

@@ -1119,32 +1119,42 @@ let generate_includes ctx ?(program_types=[]) () =
     "#include <bpf/bpf_helpers.h>";
   ] in
 
-  (* When using vmlinux.h, we don't need context-specific kernel headers *)
-  (* vmlinux.h contains all kernel types, so we only need eBPF helpers *)
-  let context_includes = [] in (* No additional kernel headers needed with vmlinux.h *)
+  (* Get context-specific includes for macros not in vmlinux.h *)
+  let context_includes = List.fold_left (fun acc prog_type ->
+    let context_type = match prog_type with
+      | Ast.Tc -> Some "tc"
+      | _ -> None
+    in
+    match context_type with
+    | Some ctx_type -> 
+        let includes = Kernelscript_context.Context_codegen.get_context_includes ctx_type in
+        acc @ includes
+    | None -> acc
+  ) [] program_types in
 
   (* Remove duplicates between all include sets *)
   let all_base_includes = vmlinux_includes @ standard_includes in
   let unique_context_includes = List.filter (fun inc -> 
     not (List.mem inc all_base_includes)) context_includes in
 
-  (* For kprobe programs, only emit kprobe includes which contain everything needed *)
+  (* For kprobe programs, still use vmlinux.h but include context-specific macro headers *)
   let has_kprobe = List.exists (function Ast.Kprobe -> true | _ -> false) program_types in
   if has_kprobe then (
-    (* With vmlinux.h, we only need it and eBPF helpers, no additional kernel headers *)
+    (* Use vmlinux.h and context-specific headers for macros *)
     let vmlinux_and_helpers = [
       "#include \"vmlinux.h\"";
       "#include <bpf/bpf_helpers.h>";
     ] in
 
     List.iter (emit_line ctx) vmlinux_and_helpers;
+    List.iter (emit_line ctx) unique_context_includes;
     emit_blank_line ctx
   ) else (
     (* For non-kprobe programs, use vmlinux.h and standard processing *)
     let all_includes = vmlinux_includes @ standard_includes @ unique_context_includes in
     List.iter (emit_line ctx) all_includes;
     emit_blank_line ctx;
-        
+
     (* Use proper kernel implementation: extern declarations and macros *)
     emit_line ctx "extern void *bpf_obj_new_impl(__u64 local_type_id__k, void *meta__ign) __ksym;";
     emit_line ctx "extern void bpf_obj_drop_impl(void *p__alloc, void *meta__ign) __ksym;";